Plans for the next year for the Head Injury Clinical Center Program are: 1) The prototype of the brain state analyzer which is now in use in the Neurosurgical Intensive Care Unit will be replaced with the 2nd generation of the brain state analyzer. This equipment will require very little manual control for operation. In addition there will be on line automatic statistical analysis with immediate display of Z transforms of the EEG frequency spectrum and averaged evoked potentials to visual, auditory and somatosensory stimuli in a histogram form. A brain stem vector will be completed on line and displayed in a histogram form for the management and study of the severe brain injured patients who are being treated with barbiturate hibernation. 2) Cats with electrolytic mesencephalic lesion will have seqential determinations of their brain stem vectors which are the resultants of the evoked response to visual, auditory and somatosensory stimuli. The electrophysiological changes as the cats recover from their lesions is a model of the recovery as seen in patients who recover from brain stem injury due to head trauma. This data will provide a basic understanding of the relationship between brain stem pathology and the resultant electrophysiological changes. 3) Xenon studies developed toward determination of the regulation of cerebral blood flow and oxygen metabolism by non-invasive techniques have been developed though the stage of equipment design and actual equipment development is about to be undertaken. 4) Projects proposed but not funded include in the clinical realm application of high dose barbiturate therapy in patients with severe head injury and in the laboratory the evaluation of Na plus K plus ATPase turnover mechanisms of reduction of brain glucose utilization and blood flow, axonal sprouting, production and inhibition of encephalogenic myocardial lesions and alterations of defined measures of behavioral and electrophysiological activity which will provide a basis for the development of a functional activity scale to evaluate techniques to facilitate closely related animal experiments, to define key mechanisms of fluidity changes in membrane lipid structure and metabolism after traumatic ischemia and study the possible role of barbiturates in reversing this process.